Well plugging and whipstocking



D. B. GRABLE ETAL WELL PLUGGING AND WHIPSTOCKING May 23, 1950 INVENTORS ATTORNEY 2 Sheets-Sheet l G20/mm3. Gm? 23 .u .n z a .u .l ,www www i .4.1. 1,5% .l2 .4. .a n. a. .u

Filed Aug. 10, 1945 May 2.3, 1950 D. B. GRABLE Erm.

WELL PLUGGING AND WHIPSTOCKING 2 Sheets-Sheet 2 Filed Aug. 10, 1945 Patented May 23, 1950 UN IT ED WELL PLUGGIN G vAND `WHIPSTOCKING Donovan B. Grable,'Long Beach, and JohnM. Jackson, Santa Monica, Calif.

Application August 10, 1945, Serial No. 6105062 (Cl. Z55-L6) A 22 Claims. 1

This invention .has to do with open (uncased) hole plugging and whipstocking operations in oil wells, and has for its general vobject to provide improvements in open hole plugs and Whipstocks, and methods for their placement and use, having various vimportant advantages over the types of plugs, Whipstocks and methods heretofore employed.

Considering rst the conventional practices in open hole whipstocking'the customary procedure has been to first place in the unca-sed hole a cement plug to serve asa footing for a Whipstock later to be run into the Well after the rcement is set. This practice'has involved difficulties from standpoints both "of the security of the footing and the length of time necessarily consumed. `Thewe11bore wall frequently lis coated with mud to a degree rendering 'it difficult to obtain a properly strong and 'load ysustaining bond between the cement plug .and the formation. Thus failure of the bond to support vthe plug weight or the subsequently applied load necessitates a repluggin'g operation. After the rplug cement is placed in the hole it is necessary `to wait a considerable period -of time for the cement to harden suiliciently to serve as a firm or hard footing for the ewhipstock, thus entailing vconsiderable expense in view Aof the idleness of equipment and workers While the vcement is lreaching a hardened condition.

One major object of the invention is to provide improved methods Vand equipment whereby -in virtually one continuous sequence, the whipstock may be oriented and -rmlyset v'in the hole, followed immediately by offset drilling. The invention contemplates the .use of a .novel Whipstock comprising .a plug body particularly designed for use in open hole by the provision of expansible means adapted to penetrate the formation and securely anchor the Whipstock in place. As Will appear, the whipstock may be run into the well on a pipe string carrying a cutting tool to which the whipsto'ck is detachably connected, and .the body `of the whipstock is provided with an initially open passage permitting fluid circulation through, and up around the whipstock during its lowering to itsproper depth. With provision thus made for Ymechanically interlocking the plug with the formation, no dilliculties are encountered by Areason of mud cake on the bore wall. In fact, maintenance of the described fluid circulation, together with permissible proximity of the plug to the -bore wall, permits substantial removal -of the mud lm.

After being set in position as described, the whipstock may be `adequately supported to rvpermit immediate -startmg fof deflected drilling.

However, it may be preferred, for various reasons, first to 'cement the plugin place, or to form a cement plug in the hole below the whipstock. Accordingly, after the Whipstock 'is anchored to the formation, cement may be pumped down through the pipe string and whipstock to a .dis-

A further feature of the invention is the use inV conjunction with a Whipsto'ck or plug, of an extended tail `pipe through which circulation and cement discharge may be maintained to any desired depth belowthe whipstock or plug. As will later appear, this feature may be `employed to advantage in cementing about and drilling past a iish lodged Aat Ian intermediate location in the Well.

While reference has been made to the use of a combined plug and whipstock, the invention also contemplates an improved open hole plug having the described structural and operative characteristics except those features attributable to the whipstock 'as such. The hereinafter described form of simple plug may be used, among various purposes, as a footing for a whipstock to be subsequently run into the well, the plug itself having the characteristic advantage, withV or without cementing, and providing yimmediately upon being expanded into l'the formation, a strong and hard surface whipstoc'k support. Accord` ingly, immediately iafter setting of `the plug, the' is a fragmentary view .showing theY the pins projected and locked into the formation.

Referring first to Figs. 1 and 2 illustrating one embodiment of the invention in an open hole whipstock, the whipstock comprises an elongated cylindrical body generally indicated at II), which preferably is made of a suitable drillable material, typically concrete I I. The upper end of the body may be formed as a metallic whipstock head I2, which may also be of drillable material but of sufficient hardness to deiiect or whipstock the cutting tool, except under circumstances where it may be desired to so confine or direct a type of cutting tool that will drill through the plug, if for any reason disintegration of the plug is desired. The body I9 contains a longitudinal fluid passage I3 formed typically by an upper pipe section I4 joined by coupling I5 with any desired number of sections I6 interconnected by couplings I1. in the plug at an inclination with the vertical axis of the plug, as and for the purposes later described. Section I8 is connected by couplings I9 and 29 with a bottom connector 2l which initially contains a frangible seat 22 held in place by the fitting 23.

Referring to Figs. 6 and '7, the body I0 contains a vertical series of fluid pressure operable formation penetrating elements or assemblies, generally indicated at 24, which may be provided in any suitable number and arrangement as required for rm anchoring and stabilization of the body within the bore hole. Each of the assemblies 24 is shown typically to comprise four cylinders 25 arranged at 90 and threaded at 26 into the coupling I1. The outer ends of the cylinders 25 are closed by heads 21, and the cylinders contain pistons '28 carrying pins 29 which are radially projectible through openings 30 into the formation 3'I by iiuid pressure communicated from passage I3 through the coupling openings 32 to the pistons 28. In order to assure retention of the pins 29 in their expanded or formation penetrating positions, see Fig. '7, the pins may carry spring-expanded latch elements 33 which are passable through the openings 30 and thereafter caused to expand and engage the heads 21 to lock the pins against inward movement.

The whipstock is lowered into the uncased well bore 35 on a pipe string 36 carrying a cutting tool, for example the drill bit 31, to which the whipstock is releasably connected by a joint 38 capable ofV supporting the whipstock and transmitting thereto turning movement of the pipe string, and capable also of conducting fluid from the pipe string into the passage I 3. Typically the joint 38 is shown to consist of a drillable pipe 39 having at 4I! a left-hand thread connection with the bit, and carrying on its lower end a head 4I having splined engagement at 42 within the pipe section i4. By reference to Fig. 2 it will be observed that the relative lengths of the pipes I4 and 39 are such that when the latter is disconnected from the drill bit, it may drop into and be A lower pipe section I8 is positionedr 4 received within pipe I4 below the deflecting face 43 of the whipstock. As the drawing shows, while the whipstock is being lowered, it is supported by the interengagement of shoulder 44 and 45 respectively on the pipes 4I and I4.

In operation, the whipstock plug is lowered into the bore 35 on the pipe string 33 in the condition illustrated by Fig. l. Assuming the whipstock to be lowered to proper depth, it may then be desirable to orient the body I0 to bring the whipstock face into the position of horizontal angularity required for deflection of the bit 31 in the proper direction. Forthis purpose, a surveying instrument, conventionally indicated at 46 is lowered on cable 41 through the pipe string and joint 38 into the inclined section I8 of the plug passage. 'Ihe instrument 46 may be of any of the known types, for example a so-called single shot, capable of indicating or measuring the horizontal angular direction of the passage inclination, and therefore the horizontal angular position of the whipstock face 43, since the latter has a xed relation to the inclination of the pipe section I8. By rotational adjustment of the whipstock in the well bore, it may be properly oriented as determined by readings of instrument 46.

Ordinarily it will be desirable to maintain fluid circulation through the whipstock during a portion or the entirety of its travel while being lowered to setting position within the well. Circulation is maintained by pumping mud through the drill pipe,` joint 38 and the plug passage I3. It may be advantageous for such purposes as later described, to circulate the fluid or cement to a discharge location substantially below the lower end of the whipstock. For this purpose, the body I0 may carry an extended depending tail pipe 50 connected to the coupling 2 I. Main-Y tenance of uid circulation of course tends to facilitate lowering of the whipstock within an otherwise restricted well, and to clean out the space between the whipstock body and the bore wall. At this point it may be mentioned that in order to assure maximum support and stability of the plug when anchored or set in the hole, the plug diameter may be made to correspond closely to the well bore diameter. In some instances the plug may have a, snug or even fairly tight nt within the bore.

Assuming the whipstock to be properly oriented in the well, an object such as the metal ball 43' may be dropped through the pipe string and plug passage to seat upon and substantially close or restrict the opening 49 in the seat 22, to permit the development of suficiently high fluid pressure in the passage I3 to expand the pins 29 into the formation as shown in Fig. 2. Thereafter, by further increasing the fluid pressure, the frangible seat 22 may be ruptured and the ball 48 blown out through the plug or tail pipe to again open the passage i3.

With the whpstock thus anchored in the hole, whipstock drilling may be started by disconnecting the bit from pipe 39. Ordinarily however it is preferred first to cement the plug in place. Accordingly, after displacement of the ball 49, cement may be pumped down through the plug, and tail pipe if used, into the well bore below the plug, and if desired in quantities such that the cement will flow partially or entirely up around the anchored plug. The latter thus is set to permit immediate whipstock drilling, a

` feature of considerable importance, since in cona tail pipe communicating with said passage and depending below the plug.

6. A well plug adapted to be lowered on a pipe string into an uncased hole, comprising a body having a top whipstock end and containing a passage for conducting fluid through the plug.

a formation cutting tool carried by said pipe string, tubular means releasably connecting said tool with the plug and said passage, iiuid pressure actuated means operable to penetrate the formation to hold the plug in position in the hole, and means for temporarily,1 closing fluid discharge through said passage.

'7. A well plug adapted to be lowered on a pipe string into an uncased hole, comprising a body having a top whipstock end and containing a passage for conducting fluid through the plug, a formation cutting tool carried by said pipe string, tubular means made of drillable metal releasably connecting said tool with the plug and said passage, and fluid pressure actuated means operable to penetrate the formation to hold the plug in position in the hole. y

8. A well plug adapted to be lowered on a pipe string into an uncased hole, comprising a body having a top whipstock end and containing a passage for conducting fluid through the plug, a formation cutting tool carried by said pipe string, tubular m'eans releasably connecting said tool with the plug and said passage, and iluid pressure actuated means operable to penetrate the formation to hold the plug in position in the hole, said tubular means being movable down into the plug below said whipstock end upon disconnection from said tool. Y

9. A well plug adapted to be lowered on a pipe string into an uncased hole, comprising a body having a top whipstock end and containing a normally open passage permitting fluid circulation through theplug while being lowered, means for substantially closing fluid discharge through said passage, means then radially expansible by the iiuid pressure in said passage to penetrate the formation and hold the plug in set position within the hole, a formation cutting tool carried by said pipe string, tubular means releasably connecting said tool with the plug and said passage, said connecting means being vertically movable relative to the body and being operable to rotate the plug upon rotation of the pipe string, cement being flowable through said connecting means and passage below and around the plug, and the connecting means then being disconnectable from the cutting tool.

10. A plug adapted to be lowered on a suspension means and set in an uncased hole, said plug including a vertically elongated body having an upper whipstock portion and containing a longitudinal passage having at least one portion inclined with respect to the verticalv axis of the body for reception of an instrument to determine the orientation of said whipstock portion of the body, said passage extending from its top in a course of downward directness permitting the instrument to be lowered by gravity into said inclined portion.

1i. A plug adapted to be lowered on a pipe string and set in an uncased hole, said plug comprising a vertically elongated body having an upper whipstock portion and containing a longitudinal passage having at least one portion inclined with respect to the vertical axis-of the bodt for reception of an instrument run down through the pipe string to determine the orient/ation of said whipstock portion of the body,- said passage extending from lts top in a course of downward directness permitting the instrument to be lowered by gravity into said inclined portion and means releasably connecting said passage and plug with the pipe string.

12. A whipstock adapted to be lowered on a pipe string and set in an uncased hole, comprising a vertically elongated body of drillable material containing, a tube in said body and connectible with said pipe string, a portion of the Atube being inclined with respect to the vertical axis of the body for reception of an instrument to determine the orientation of the body, said tube extending from its top in a course of downward directness permitting the instrument to be lowered by gravity into said inclined portion thereof.

13. A whipstock adapted to be lowered on a pipe string and set in an uncased hole, comprising a vertically elongated body of drillable material containing, a tube in said body and connectible with said pipe string, a straight portion of the tube being coaxial with the body and another portion of the tube being inclined with respect to the vertical axis of the body for reception of an instrument to determine the orientation of the body, and means in the body opposite said straight portion of the tube and operable by the iiuld pressure therein to penetrate the formation and anchor the body therein.

14. A plug adapted to be lowered on a pipe string into an uncased hole, comprising an initially open passage permitting fluid circulation downwardly through the plug while being lowered, means expansible by fluid pressure in said passage to penetrate the formation and hold the plug in set position within the hole, and a closure below said expansible means for temporarily substantially closing downward fluid discharge through said passage to actuate said expansible means and displaceable to againpermit fluid flow downwardly through said passage and upwardly `about the plug after penetration of the formation by said expansible means.

l5. A plug adapted to be lowered on a pipe string into an uncased hole, comprising an initially open passage permitting fluid circulation downwardly through the plug while being lowered, a closure for substantially closing downward iluid discharge through said passage, and means above said closure then radially expansible by the fluid pressure in said passage to penetrate the formation and hold the plug in set position within the hole, said closure being displaceable out of the plug and into the well to permit fluid flow downwardly through said passage and upwardly about the plug after penetration of the formation by said expansible means.

16. A plug adapted to be lowered on a pipe string into an uncased hole, comprising an initially open passage permitting fluid circulation downwardly through the plug while being lowered, a closure for substantially closing fluid discharge through said passage, means above said closure then radially expansible by relatively low fluid pressure in said passage to penetrate the formation and hold the plug in set position within the hole, said closure being displaceable in response to the communication of relatively high lluid pressure to said passage to permit lluid ow downwardly through said passage and upwardly about the pipe.

V- 17. A plug adapted to be lowered on a pipe string into an uncased hole, comprising an initially open passage permittingA uld circulation downwardly through the plug while being lowered, a closure for substantially closing uid discharge downwardly through said passage, means above said closure then radially expansible by relatively low uid pressure in said passage to penetrate the formation and hold the plug in set position within the hole, said closure being displaceable in response to the communication of relatively high fluid pressure to said passage to permit fluid flow downwardly through said passage and upwardly about the pipe, and an extended tail pipe depending from the plug below said closing means.

18. A plug adapted to be lowered on a pipe string into an uncased hole, comprising an initially open passage permitting fluid circulation downwardly through the plug while being lowered, releasable means for closing said passage, and fluid pressure actuated means above said closing means operable to penetrate the formation to hold the plug in set position within the hole, said means comprising a plurality of radially expansible pins having inner piston ends eX- posed to the fluid pressure in said passage and outer ends adapted to penetrate the formation, and means for locking said pins in expanded positions.

19. A plug adapted to be lowered on a pipe string into an uncased hole, comprising an elongated concrete body, tubular means extending longitudinally through the plug and connected to said pipe string, fluid circulation being permitted downwardly through a passage formed by said tubular means while the plug is being lowered in the well, radial cylinders communicating with said passage, expansible pins having inner piston ends contained within said cylinders and outer ends adapted to penetrate the formation, means below said cylinders for substantially closing fluid circulation through said passage, said pins then being radially expansible by relatively low fluid pressure applied to said pistons, said passage closing means being displaceable in response to the communication of relatively high fluid pressure to said passage to permit fluid flow downwardly through said passage and upwardly about the pipe.

20. A plug adapted to be lowered on a pipe string into an uncased hole, comprising a concrete body having a top metallic whipstock end and containing a tube forming an initially open passage permitting fluid circulation downwardly through the plug while being lowered, a closure for substantially closing downward uid discharge through said passage, and iiuid pressure actuated means above the closure then operable to penetrate the formation to hold the plug in set position within the hole, said closure being displaceable to permit fluid flow downwardly through said passage and upwardly about the plug after penetration of the formation by said fluid pressure actuated means.

21. A plug adapted to be lowered on a pipe string into an uncased hole, comprising a nonmetallic body having a top metallic whipstock end and containing a metal tube forming an initially open passage permitting uid circulation through the plug while being lowered, a closure for substantially closing downward fluid discharge through said passage, and fluid pressure actuated means above the closure then operable to penetrate the formation to hold the plug in set posi* tion within the hole, said closure being displaceable to permit fluid flow downwardly through said passage and upwardly about the plug after penetration of the formation by said iiuid pressure actuated means.

22. A plug adapted to be lowered on a pipe string into an uncased hole, comprising an initially open passage permitting fluid circulation downwardly through the plug while being lowered, frangible closure seat means in said passage, a drop-in closure adapted to engage said seat means and temporarily close said passage against downward circulation of fluid, and means then expansible by the uid pressure in said passage to penetrate the formation and hold the plug in set position within the hole, said seat means being rupturable by the fluid pressure after actuation of said expansible means to again permit downward circulation of fluid.

DONOVAN B. GRABLE. J. M. JACKSON.

REFERENCES CTED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,188,001 May June 20, 1916 1,821,426 Dumm et al Sept. 1, 1931 1,835,227 Lane et al. Dec. 8, 1931 1,923,448 McCoy et al. Aug. 22, 1933 1,951,638 Walker Mar. 20, 1934 2,179,832 Smith Nov. 14, 1939 2,222,014 Baker Nov. 19, 1940 2,281,414 Clark Apr. 28, 1942 

